Managing Corpses From Different Castes in the Eastern Subterranean Termite

Abstract

Abstract Corpse management is essential for social animals to maintain colony health. In the eastern subterranean termite, Reticulitermes flavipes, workers carry out undertaking behaviors to mitigate the risks associated with the dead. In this study, we hypothesized that termites would respond differently to the corpses from different castes based on their postmortem chemical signatures. To test this hypothesis, we 1) documented the behavioral responses of the workers toward corpses from different castes, and 2) profile the chemical signatures of these corpses. Corpses from all castes were retrieved inside the nests and cannibalized when they were decomposed <64 h, regardless of the presence or absence of the cues that we refer to as early death cues (3-octanol and 3-octanone). However, after 64 h, all corpses except for soldiers were buried on site by R. flavipes workers. The late death cues (oleic acid) were cumulative over time among castes but accumulated more slowly and at lower levels in soldiers. The differential release of 3-octanol and 3-octanone between workers/soldiers and nymphs could be explained by either qualitative or quantitative differences in signaling the death between imaginal and neuter developmental pathways. In summary, the efficient and selective recognition of the dead and the fine-tuning of subsequent undertaking responses observed in R. flavipes are aspects of corpse management, which can minimize the potential risks associated with different castes and maximize the colony fitness.